consistent error message on deserialization failure

cassandra/obj_parser.pyx

@@ -14,6 +14,7 @@
 
 include "ioutils.pyx"
 
+from cassandra import DriverException
 from cassandra.bytesio cimport BytesIOReader
 from cassandra.deserializers cimport Deserializer, from_binary
 from cassandra.parsing cimport ParseDesc, ColumnParser, RowParser
@@ -67,8 +68,12 @@ cdef class TupleRowParser(RowParser):
 
             # Deserialize bytes to python object
             deserializer = desc.deserializers[i]
-            val = from_binary(deserializer, &buf, desc.protocol_version)
-
+            try:
+                val = from_binary(deserializer, &buf, desc.protocol_version)
+            except Exception as e:
+                raise DriverException('Failed decoding result column "%s" of type %s: %s' % (desc.colnames[i],
+                                                                                             desc.coltypes[i].cql_parameterized_type(),
+                                                                                             str(e)))
             # Insert new object into tuple
             tuple_set(res, i, val)
 

cassandra/protocol.py

@@ -651,7 +651,7 @@ class ResultMessage(_MessageType):
                 except Exception as e:
                     raise DriverException('Failed decoding result column "%s" of type %s: %s' % (colnames[i],
                                                                                                  coltypes[i].cql_parameterized_type(),
-                                                                                                 e.message))
+                                                                                                 str(e)))
         return paging_state, coltypes, (colnames, parsed_rows)
 
     @classmethod

cassandra/row_parser.pyx

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 from cassandra.parsing cimport ParseDesc, ColumnParser
+from cassandra.obj_parser import TupleRowParser
 from cassandra.deserializers import make_deserializers
 
 include "ioutils.pyx"
@@ -33,7 +34,16 @@ def make_recv_results_rows(ColumnParser colparser):
         desc = ParseDesc(colnames, coltypes, make_deserializers(coltypes),
                          protocol_version)
         reader = BytesIOReader(f.read())
-        parsed_rows = colparser.parse_rows(reader, desc)
+        try:
+            parsed_rows = colparser.parse_rows(reader, desc)
+        except Exception as e:
+            # Use explicitly the TupleRowParser to display better error messages for column decoding failures
+            rowparser = TupleRowParser()
+            reader.buf_ptr = reader.buf
+            reader.pos = 0
+            rowcount = read_int(reader)
+            for i in range(rowcount):
+                rowparser.unpack_row(reader, desc)
 
         return (paging_state, coltypes, (colnames, parsed_rows))